Quantum wire lasers are generally fabricated through complex overgrowth processes with molecular beam epitaxy. The material systems of such overgrown quantum wires have been limited to Al-Ga-As-P, which leads to emission largely in the visible region. We describe a simple, one-step chemical vapor deposition process for making quantum wire lasers based on the Al-Ga-N system. A novel quantum-wire-in-optical-fiber (Qwof) nanostructure was obtained as a result of spontaneous Al-Ga-N phase separation at the nanometer scale in one dimension. The simultaneous excitonic and photonic confinement within these coaxial Qwof nanostructures leads to the first GaN-based quantum wire UV lasers with a relatively low threshold.